Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1054805 | ENA |
REPOSITORIES: ENA
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Project description:Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype and has the highest rate of recurrence1. The predominant standard of care for advanced TNBC is systemic chemotherapy with or without immunotherapy, however responses are typically short-lived1,2. Thus, there is an urgent need to develop more effective treatments. PI3K pathway components represent plausible therapeutic targets, as approximately 70% of TNBCs have PIK3CA/AKT1/PTEN alterations3–6. However, unlike hormone receptor-positive tumors, it is still unclear if or how PI3K pathway inhibitors will be effective in triple-negative disease7. Here we identify a promising AKT inhibitor-based therapeutic combination for TNBC. Specifically, we show that AKT inhibitors potently synergize with agents that suppress the histone methyltransferase, EZH2, and promote robust tumor regression in multiple TNBC models in vivo. AKT and EZH2 inhibitors exert these effects by first cooperatively driving basal-like TNBC cells into a more differentiated, luminal-like state, which cannot be effectively induced by either agent alone. Once differentiated, these agents kill TNBCs by hijacking signals that normally drive mammary gland involution. Finally, using machine learning approach, we developed a classifier that can be used for patient selection. Together these findings identify a promising therapeutic strategy for this highly aggressive tumor type and illustrate how deregulated epigenetic enzymes can insulate tumors from oncogenic vulnerabilities. These studies also reveal how developmental tissue-specific cell death pathways may be co-opted for therapeutic benefit.
2024-07-08 | GSE252382 | GEO
Project description:Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype and has the highest rate of recurrence1. The predominant standard of care for advanced TNBC is systemic chemotherapy with or without immunotherapy, however responses are typically short-lived1,2. Thus, there is an urgent need to develop more effective treatments. PI3K pathway components represent plausible therapeutic targets, as approximately 70% of TNBCs have PIK3CA/AKT1/PTEN alterations3–6. However, unlike hormone receptor-positive tumors, it is still unclear if or how PI3K pathway inhibitors will be effective in triple-negative disease7. Here we identify a promising AKT inhibitor-based therapeutic combination for TNBC. Specifically, we show that AKT inhibitors potently synergize with agents that suppress the histone methyltransferase, EZH2, and promote robust tumor regression in multiple TNBC models in vivo. AKT and EZH2 inhibitors exert these effects by first cooperatively driving basal-like TNBC cells into a more differentiated, luminal-like state, which cannot be effectively induced by either agent alone. Once differentiated, these agents kill TNBCs by hijacking signals that normally drive mammary gland involution. Finally, using machine learning approach, we developed a classifier that can be used for patient selection. Together these findings identify a promising therapeutic strategy for this highly aggressive tumor type and illustrate how deregulated epigenetic enzymes can insulate tumors from oncogenic vulnerabilities. These studies also reveal how developmental tissue-specific cell death pathways may be co-opted for therapeutic benefit.
2024-07-08 | GSE251708 | GEO
Project description:Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype and has the highest rate of recurrence1. The predominant standard of care for advanced TNBC is systemic chemotherapy with or without immunotherapy, however responses are typically short-lived1,2. Thus, there is an urgent need to develop more effective treatments. PI3K pathway components represent plausible therapeutic targets, as approximately 70% of TNBCs have PIK3CA/AKT1/PTEN alterations3–6. However, unlike hormone receptor-positive tumors, it is still unclear if or how PI3K pathway inhibitors will be effective in triple-negative disease7. Here we identify a promising AKT inhibitor-based therapeutic combination for TNBC. Specifically, we show that AKT inhibitors potently synergize with agents that suppress the histone methyltransferase, EZH2, and promote robust tumor regression in multiple TNBC models in vivo. AKT and EZH2 inhibitors exert these effects by first cooperatively driving basal-like TNBC cells into a more differentiated, luminal-like state, which cannot be effectively induced by either agent alone. Once differentiated, these agents kill TNBCs by hijacking signals that normally drive mammary gland involution. Finally, using machine learning approach, we developed a classifier that can be used for patient selection. Together these findings identify a promising therapeutic strategy for this highly aggressive tumor type and illustrate how deregulated epigenetic enzymes can insulate tumors from oncogenic vulnerabilities. These studies also reveal how developmental tissue-specific cell death pathways may be co-opted for therapeutic benefit.
2024-07-08 | GSE250632 | GEO
Project description:The lysine methyltransferase EZH2 is overexpressed in colorectal cancer (CRC) and has been found to be positively and negatively correlated with CRC patient survival depending on the study suggesting that EZH2 has a complex role in CRC. Here, we demonstrate that AKT-mediated EZH2 S21 phosphorylation induced EZH2 to trimethylate β-catenin at K49, which increased β-catenin’s binding to the chromatin. Additionally, EZH2-mediated β-catenin trimethylation induced β-catenin’s interaction with TCF1 and RNA polymerase II and resulted in a dramatic gain in genomic regions with β-catenin occupancy. Interestingly, EZH2 catalytic inhibition decreased stemness but increased migratory phenotypes of CRC cells with active AKT. Overall, we demonstrated that EZH2 modulates AKT-induced changes in gene expression through the AKT/EZH2/β-catenin axis in CRC. Our results suggest that EZH2 inhibitors have tumor-inhibiting and promoting effects in CRC as they inhibit EZH2-mediated methylation of histone and non-histone targets like β-catenin.
2023-08-23 | GSE226587 | GEO
Project description:The lysine methyltransferase EZH2 is overexpressed in colorectal cancer (CRC) and has been found to be positively and negatively correlated with CRC patient survival depending on the study suggesting that EZH2 has a complex role in CRC. Here, we demonstrate that AKT-mediated EZH2 S21 phosphorylation induced EZH2 to trimethylate β-catenin at K49, which increased β-catenin’s binding to the chromatin. Additionally, EZH2-mediated β-catenin trimethylation induced β-catenin’s interaction with TCF1 and RNA polymerase II and resulted in a dramatic gain in genomic regions with β-catenin occupancy. Interestingly, EZH2 catalytic inhibition decreased stemness but increased migratory phenotypes of CRC cells with active AKT. Overall, we demonstrated that EZH2 modulates AKT-induced changes in gene expression through the AKT/EZH2/β-catenin axis in CRC. Our results suggest that EZH2 inhibitors have tumor-inhibiting and promoting effects in CRC as they inhibit EZH2-mediated methylation of histone and non-histone targets like β-catenin.
2023-08-23 | GSE226584 | GEO
Project description:The lysine methyltransferase EZH2 is overexpressed in colorectal cancer (CRC) and has been found to be positively and negatively correlated with CRC patient survival depending on the study suggesting that EZH2 has a complex role in CRC. Here, we demonstrate that AKT-mediated EZH2 S21 phosphorylation induced EZH2 to trimethylate β-catenin at K49, which increased β-catenin’s binding to the chromatin. Additionally, EZH2-mediated β-catenin trimethylation induced β-catenin’s interaction with TCF1 and RNA polymerase II and resulted in a dramatic gain in genomic regions with β-catenin occupancy. Interestingly, EZH2 catalytic inhibition decreased stemness but increased migratory phenotypes of CRC cells with active AKT. Overall, we demonstrated that EZH2 modulates AKT-induced changes in gene expression through the AKT/EZH2/β-catenin axis in CRC. Our results suggest that EZH2 inhibitors have tumor-inhibiting and promoting effects in CRC as they inhibit EZH2-mediated methylation of histone and non-histone targets like β-catenin.
2023-08-23 | GSE226588 | GEO
Project description:Triple-negative breast cancer (TNBC) is responsible for a disproportionate number of breast cancer deaths due to its molecular heterogeneity, high recurrence rate and lack of targeted therapies. Dysregulation of the phosphoinositide 3-kinase (PI3K)/AKT pathway occurs in approximately 50% of TNBC patients. We performed a genome-wide negative selection CRISPR/Cas9 screen with PI3K and AKT inhibitors to identify targetable synthetic lethalities in TNBC. We found that cholesterol homeostasis is a collateral vulnerability with AKT inhibition. Disruption of cholesterol homeostasis with pitavastatin synergized with AKT inhibition to induce TNBC cytotoxicity in vitro, in mouse TNBC xenografts and in patient-derived organoids of estrogen receptor (ER)-negative breast cancer. Neither ER-positive breast cancer cell lines nor ER-positive organoids were sensitive to combined AKT inhibitor and pitavastatin. Mechanistically, TNBCs show dysregulated SREBP-2 activation in response to single agent or combination AKT inhibitor and pitavastatin, and this was rescued by inhibition of the cholesterol trafficking protein Niemann-Pick C1 (NPC1). NPC1 loss promoted lysosomal cholesterol accumulation, decreased endoplasmic reticulum cholesterol levels and promoted SREBP-2 activation. Taken together, these data identify a TNBC-specific vulnerability to the combination of AKT inhibitors and pitavastatin mediated by dysregulated cholesterol trafficking. This work motivates combining AKT inhibitors with pitavastatin as a therapeutic modality in TNBC.
2024-01-14 | GSE252944 | GEO
Project description:Triple negative breast cancer (TNBC) is a heterogeneous and clinically aggressive disease for which there is no targeted therapy. Here we report the preferential and high sensitivity of TNBCs to BET bromodomain inhibitors such as JQ1 manifested by cell cycle arrest in early G1, apoptosis, and induction of markers of luminal epithelial differentiation in vitro and in vivo. The sensitivity of TNBC and other tumor types to BET inhibition establishes a rationale for clinical investigation, and a motivation to understand mechanisms of resistance. After engendering acquired resistance to BET inhibition in previously sensitive TNBCs, we utilized integrative approaches to identify a unique mechanism of epigenomic resistance to this epigenetic therapy. Resistant cells remain dependent on BRD4, confirmed by RNA interference. However, TNBC cells adapt to BET bromodomain inhibition by re-recruitment of unmutated BRD4 to super-enhancers, now in a bromodomain-independent manner. Proteomic studies of resistant TNBC identify hyper-phosphorylation of BRD4 and strong association with MED1. Together, these studies provide a rationale for BET inhibition in TNBC and argue for combination strategies to anticipate clinical drug resistance. ChIP-seq in parental and JQ1 resistant triple negative breast cancer (TNBC) in response to DMSO or JQ1 treatment
2016-01-07 | E-GEOD-63581 | biostudies-arrayexpress
Project description:Triple negative breast cancer (TNBC) is a heterogeneous and clinically aggressive disease for which there is no targeted therapy. Here we report the preferential and high sensitivity of TNBCs to BET bromodomain inhibitors such as JQ1 manifested by cell cycle arrest in early G1, apoptosis, and induction of markers of luminal epithelial differentiation in vitro and in vivo. The sensitivity of TNBC and other tumor types to BET inhibition establishes a rationale for clinical investigation, and a motivation to understand mechanisms of resistance. After engendering acquired resistance to BET inhibition in previously sensitive TNBCs, we utilized integrative approaches to identify a unique mechanism of epigenomic resistance to this epigenetic therapy. Resistant cells remain dependent on BRD4, confirmed by RNA interference. However, TNBC cells adapt to BET bromodomain inhibition by re-recruitment of unmutated BRD4 to super-enhancers, now in a bromodomain-independent manner. Proteomic studies of resistant TNBC identify hyper-phosphorylation of BRD4 and strong association with MED1. Together, these studies provide a rationale for BET inhibition in TNBC and argue for combination strategies to anticipate clinical drug resistance. Chem-Seq in parental and JQ1 resistant triple negative breast cancer (TNBC)
2016-01-07 | E-GEOD-63284 | biostudies-arrayexpress
Project description:The SWI/SNF chromatin remodeling complex is altered in ~20% of human cancers. ARID1A, a component of the SWI/SNF chromatin-remodeling complex, is the most frequently mutated epigenetic regulator in human cancers. Inactivation of the SWI/SNF complex is synthetically lethal with inhibition of EZH2 activity. EZH2 inhibitors are entering clinical trials for specific tumor types with SWI/SNF mutations. However, mechanisms of de novo or acquired resistance to EZH2 inhibitors in cancers with inactivating SWI/SNF mutations are unknown. Here we show that the switch of the SWI/SNF catalytic subunits from SMARCA4 to SMARCA2 drives resistance to EZH2 inhibitors in ARID1A-mutated ovarian cancer cells.
2019-02-10 | GSE110448 | GEO